This project investigates the potential of a sperm anti gen, ph-20, as an immunocontraceptive in male and female macaques. Ph-20 was first isolated from guinea pig sperm by Dr. Paul primakoff at the university of connecticut, and he has now isolated cynomolgus ph-20 and produced rabbit antibodies to cph-20. This subproject of the primate core of the contraceptive development center is evaluating the use of cDNA for ph-20 as a method for immunization of macaques. Intramuscular injection of cDNA has proven useful as a method of immunization because the cdna is absorbed into muscle cells and subsequently the antigenic protein is produced by those cells. This technique is advantagous because to adjuvant is required. Although adjuvants usually increase the immune response to an antigen, they can also cause lesions at the injection site. Prior to injection, urinary estrone and progesterone metabolites were monitored to determine cycle day of ovulation and to verify that all females were cycling normally. Eight females (four per group) have been injected with 2 different cDNAs (a soluble form and a membrane anchored form of ph-20) and boosted one month later. Serum titers for ph-20 are being monitored. Also, preimmune and post-injection samples of cervical mucus and a vaginal wash have been collected just prior to ovulation. The serum antibody response of these animals was very low, measurable only at a 1:25 dilution and non-detectable at higher dilutions. This indicates that the cdnas used are not well expressed in this model. The results of this study indicate that purified ph-20 with and antigen will need to be used in the upcoming major study of ph-20 as an immunocontraceptive.